238 TELEOSTEI. PIIYSOSTOMI. 



B. Subfamily CYPRININ^E. 



Air-bladder when present (it is absent in Homalopterd) not 

 enclosed in bone. 



In the subfamily Cyprinince, as existing in Asia, considerable 

 difficulty arises in dividing the genera into groups. 



In forming such, a very distinctive characteristic may be found 

 by observing whether the scaled edge or margin of the abdomen is 

 rounded or cutting, for in the majority of the Indian Cyprinince 

 the abdominal edge is rounded or smooth, even when somewhat 

 compressed ; whilst in a few genera the abdominal edge posterior 

 to the ventral fin is compressed, cutting, and may even be cariuated 

 as in the Clupeidce : this trenchant edge is in some continued in 

 front of the ventral fins along the thorax. 



The mouth is variously formed ; it may be transverse and inferior, 

 with or without a sucker ; the latter, if present, may occur either on 

 the lower lip or on both ; it may be narrow, of medium size, or 

 wide : anterior, and either antero-lateral or oblique. The lower jaw 

 again may be prominent, sharp or rounded, shorter than the upper, or 

 sometimes provided with a knob at the symphysis ; a movable 

 articulation may exist there, or there may be lateral prominences on 

 the mandibles. 



The lips may be exceedingly, moderately, or but slightly developed, 

 sometimes absent from one of the jaws, or closely investing both, or 

 reflected from off one, or either. There may be an uninterrupted 

 labial fold across the mandible, or portions of the lip may be much 

 developed, fringed, or crenulated. In some genera a horny or 

 cartilaginous covering to one or both lips is invariably or generally 

 present, especially in forms from the bills. 



The existence of a transverse groove across the snout can 

 scarcely be distinctive of a species, much less of a genus. Thus 

 in Discognathus lamia we find examples with rounded and smooth 

 snouts, and all intermediate forms to those with very deep trans- 

 verse grooves. The same may be seen in Labeo nukta and several 

 fishes of that genus, and even in some species of Barbus, as B. 

 dorsalis. The nearer the hills the more is the groove developed. 



The number of barbels, though not in itself character enough 

 for defining a genus, is frequently sufficient to distinguish sub- 

 genera : good examples of this may be seen in the genus Barbus, 

 or Barilius. On the other hand, in some species these appen- 

 dage smay be abnormally absent, as in Danio ; consequently sub- 

 divisions of the genus founded solely on this character would 

 lead to erroneous results. 



Groups founded on the position of the fins have for convenience' 

 sake been adopted in the following synopsis. 



The last undivided dorsal ray is variously formed, being articu- 

 lated or osseous, and in the latter case may be smooth or den- 

 ticulated; but all these varieties are present in a single genus, as 

 Barbus. The anal fin sometimes shows peculiarities, as in the 

 Barbus apogon, C. & V., where the undivided rays are spiny. 



